Dear All, Is there a way or program that is good at providing a solid estimate of F000 using the standard mean protein electron density of 0.433 e/A**3 and a mean solvent electron density calculated from the crystallization conditions? I am wondering how the latter might affect F000 if the conditions are a bit different then the values assumed in most programs.
I am "assuming" from these two values I can calculate a pretty good estimate of F000 using: F000 = mean_electron_density*Vcell(e-), where mean_electron_density=fraction_protein*0.433 e/A**3 + fraction_solvent*mean_solvent_electron_density(e/A**3). In short, how can one calculate the average solvent density instead of using the value assumed in many programs of 0.35? I know that 4M ammonium sulphate is 0.41 and pure water is 0.33 but not sure how these values are measured (or calculated). Thanks! Joe ______________________________________________________________________________________ Joseph P. Noel, Ph.D. Arthur and Julie Woodrow Chair Investigator, Howard Hughes Medical Institute Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics The Salk Institute for Biological Studies 10010 North Torrey Pines Road La Jolla, CA 92037 USA Phone: (858) 453-4100 extension 1442 Cell: (858) 349-4700 Fax: (858) 597-0855 E-mail: n...@salk.edu Publications & Citations: http://scholar.google.com/citations?user=xiL1lscAAAAJ Homepage Salk: http://www.salk.edu/faculty/noel.html Homepage HHMI: http://hhmi.org/research/investigators/noel.html ______________________________________________________________________________________
